Crystal vibrator

ABSTRACT

A vibrator suitable for use in a timepiece is provided which includes a crystal having a torsional vibrational mode, a pair of discrete electrode tracks deposited thereon, a continuous runner defining the discrete electrode tracks and a sole conductive support member for supporting the crystal and conductively mounting the crystal, as desired. The conductive support is connected to the crystal and the material of which the conductive support is fabricated is substantially identical with the material of the crystal. The crystal and support are preferably integrally connected and most preferably, they are integrally connected along a transverse, rigid channel which extends into a thickened, elongated body member. According to a second aspect of the invention, the crystal may be mounted on an oscillator terminal tag with opposed contacts fixedly connected thereto, each contact being connected to one of the respective discrete electrode tracks deposited on the crystal. The fixed connection between the contacts and conductive support may be a solder bond which secures the vibrator to the case. This mounting provides high Q value and shock-resistance.

i United States Patent Oguchi Sept. 16, 1975 CRYSTAL VIBRATOR Primary ExaminerMark O. Budd [75] Inventor: Kikuo Oguchi, Nagano, Japan gttlirnel'y, Agent, or Fzrm-Blum, Moscov1tz, Friedman ap an [73] Assignee: Kabushiki Kaisha Suwa Seikosha,

Tok 0, Ja n y pa 57 ABSTRACT F M [22] at 1974 A vibrator suitable for use in a timepiece is provided [21] Appl. No.: 456,334 which includes a crystal having a torsional vibrational Related Application Data mode, a pair of discrete electrode tracks deposlted thereon, a continuous runner defining the discrete [63] commuanon'm'pan of 289519 Sept electrode tracks and a sole conductive support mem- 1972, abandoned.

her for supporting the crystal and conductively mounting the crystal, as desired. The conductive support is [30] Forelgn Apphcatlon Pnonty Dam connected to the crystal and the material of which the Se t. 22, 1971 Japan 46-74021 conductive Support i f b i t d i ub tantially identical with the material of the crystal. The crystal and [52] US. Cl. 3l0/9.6; 310/89; 310/94; support are referably integrally connected and most 2 310/97 preferably, they are integrally connected along a [51] hit. Cl. H01L 41/04 transverse rigid channel which extends into a thick [58] Fleld of Search 310/82, 9.l, 9.2, 9.3, ened7 elongated body men-bet According to a Second 310/94 aspect of the invention, the crystal may be mounted on an oscillator terminal tag with opposed contacts [56] References C'ted fixedly connected thereto, each contact being con- UNITED STATES PATENTS nected to one of the respective discrete electrode 2,161,980 6/1939 Runge et a1 310 96 x tracks deposited on the Crystal The fixed Connection 2,310,612 2/1943 Bremer et a1. 310/94 between the contacts and conductive support may be 2,343,738 3/1944 Bechmann et a1. 310/9.4 X a solder bond which secures the vibrator to the case. 3,6l7,780 Benjaminson el al. X mounting provides Q value and Shock 3,683,213 8/1972 Staudte 3lO/8.2 X resistance. 3,697,766 10/1972 Gamer 310/82 3 Claims, 3 Drawing Figures PATENTED SEP 115E975 SHEET 1 2 F/GI/ PATENTEB SEP 1 6 I975 SHEET 2 2 CRYSTAL VIBRATOR CROSS REFERENCE TO RELATED APPLICATION This application is a Continuation-In-Part of my copending application, Ser. No. 289,519, filed Sept. I5, 1972, now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to an improved vibrator and mounting therefor for use in a timepiece. More particularly, the instant invention relates to an improved crystal vibrator of the type having a torsional vibrational mode.

Presently, quartz crystal timepieces which employ a crystal vibrator as a time standard are available, however, such crystal vibrators generally utilize the bending vibrational mode chracteristic of a tuning fork type or bar type crystal body. Such quartz crystal vibrators, as have been employed in timepieces, are connected to a divider circuit in the timepiece which converts the high frequency signal generated thereby into a low frequency signal suitable for driving the time indication mechanism of the timepiece. However, such divider circuits drain the power source which drives the timepiece and the higher the initial frequency generated by the crystal, the greater the number of dividers that must be employed within the circuit to reduce the frequency for driving the time indication mechanism. It is well known that quartz crystals having a torsional vibrational mode generate a higher frequency signal than quartz crystals of the bending vibrational variety and therefore, the latter have been employed in timepieces until recently, since they drain the power source less than the former, thereby prolonging the life of the power source. Since crystals of the bending vibrational variety generate lower frequency signals to begin with, fewer divisions within the divider circuit have been necessary to reduce the signal into one suitable for driving the timepiece; therefore, it has been necessary to employ fewer dividers within the divider circuit allowing for compacting the divider circuit within the limited space of the timepiece and reducing the power drain of the divider circuit on the power source used to drive the timepiece.

Recently, however, with the development of integrated circuit techniques, higher frequencies can be reduced to lower frequencies without substantially increasing the number of dividers within the divider circuit thereby maintaining a compact circuit element and without providing an increasing power drain on the power source of the timepiece. Additionally, such circuits are adapted to handle several hundred kHz of frequency and suitably convert them for driving the time indication mechanism of the timepiece.

Therefore, the advent of the integrated circuit technique made it possible to replace crystals of the bending vibrational variety with crystals having a torsional vibrational mode in vibrator systems for timepieces, however, attempts heretofore undertaken have been unsuccessful. Crystals of the torsional vibrational mode are susceptible to Warpage which occurs as a result of shocks being imparted thereto, such as occur when the crystal receives a physical impact. Warpage decreases the shock resistance of 'such crystals thereby foreshortening their useful life.

Accordingly, this invention provides a crystal of the torsional vibrational variety which maybe employed in a vibrator in a timepiece which is substantially shockresistant, capable of high Q values and resistant to warpage.

SUMMARY OF THE INVENTION Generally speaking, in accordance with the invention, a vibrator suitable for use in a timepiece is provided which includes a crystal having a torsional vibrational mode, a pair of discrete electrode tracks deposited thereon, a continuous runner defining the discrete electrode tracks and a sole conductive support member for supporting the crystal and conductively mounting the crystal, as desired. The conductive support is connected to the crystal and the material of which the conductive support is fabricated is substantially identical with the material of the crystal. The crystal and support are preferably integrally connected and most preferably they are integrally connected along a transverse, rigid channel which extends into a thickened, elongated body member.

Preferably, the crystal has a rectilinear configuration and is most preferably of rectangular shape. The conductive support member is preferably connected to the crystal at a perpendicular, and most preferably the crystal is bilaterally symmetrical about a plane through the conductive support.

When the vibrator crystal is formed in accordance with the invention, the vibrator may be fixedly mounted in a housing for inclusion within the timepiece and the vibrator may be rendered shock-resistant thereby for maintaining the high Q value of the crystal.

According to a second aspect of the invention, the crystal may be mounted on an oscillator terminal tag with opposed contacts fixedly connected thereto, each contact being connected to one of the respective discrete electrode tracks deposited on the crystal. The fixed connection between the contacts and conductive support may be a solder bond which secures the vibrator to the case. This mounting provides high Q value and shock-resistance.

Accordingly, it is an object of this invention to provide a vibrator for use in a timepiece which includes a crystal having a torsional vibrational mode.

Another object of the invention is to provide a mounting for the novel crystal.

A further object of the invention is to provide a crystal of the torsional vibrational variety which may be employed in a vibrator in a timepiece and which is substantially shock-resistant, capable of high Q values and resistant to Warpage.

Still other objects and advantages of the invention will, in part, be obvious and will, in part, be apparent from the specification The Invention accordingly comprises the features of construction, combinations of elements and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view of a conventional crystal vibrator of the torsional vibrational variety and is duly labeled prior art;

1 igferringi bw to ioji wherein the prior artis show'nfa crystal barlol'of the type which vibrates torgibhaiiy is provided with an electrode coating 102 and an electrode coating 103. The walls of crystal bar 101 riiay bei'ele'ctrode coated by utilizing conventional evaporation techniques and the like. During the electiode'fcoating operation selected areas of crystal bar 101' "yqbe masked and therefore at the conclusion of the co'a ting'process continuous gap 104 is provided between neighboring electrodes 102 and 103. Conductive thiriwi'res 105 and 105' are respectively connected at one of their ends to electrode 102 and 103 and serve to support crystal bar 101 on respective coupling leads l06==and 106 to'which they are connected "at their other respective ends. Conventionally in a timepiece, for instance, a liquid crystal display device, the crystal vibrator is-co'upled by coupling leads 106,106 to oscillator a'nd divider circuits wherein the high frequency oscillation generated by the crystal vibrator is reduced by the divider circuit to low frequency timing signals which are transferred to a decoder circuit. Ordinarily, the decoder circuit produces an output which is transferred to a driving circuit and when it is desired to read the time indicated by the timepiece a booster circuit is actuated, for instance, by a manually operable switch and supplies the high voltage necessary for actuating selected elements of the liquid crystal display device.

Such prior art crystal vibrators are usually either selfcontained within their own housing, or they are contained within the timepiece case and such housings and cases are generally small in size. Prior art crystal vibrators of the type described which are suspended on thin wire supports are apt to physically contact an inner wall of their housing or case when conductive thin wire supports 105, 105' are connected to electrodes 102, 103 or coupling leads 106, 106 in a somewhat imprecise manner. In the event that conductive wire supports 105, 105 are precisely connected to electrodes 102, 103 and coupling leads 106, 106', crystal bar 101 may still physically contact its housing or case when such housing or case receives a shock, for instance, an impact, as is likely to occur when such timepiece is worn, moved, and the like. The shock-resistance of such conventional crystal vibrators cannot be increased by increasing the rigidity of conductive thin wire supports 105, 105' for strengthening their connection to electrodes 102, 103 and coupling leads 106, 106' because the Q value of the vibrator is lowered thereby. The disadvantages of such conventional torsion type crystal vibrators is overcome by the crystal vibrator construction of the present invention.

Referring now to FIG. 2, which shows a preferred imlike techniques. Prior to deposition of the electrode tracks, selected areas of crystal 3 may be masked, as hereinbefore described, by one or more known masking methods and at the conclusion of the coating process continuous runner 8 is provided between neighboring-electrodes 5 and 6. Crystal 3, preferably at the mid-portion thereof, is integrally connected to indexing or conductive support 4 by which the crystal vibrator may be firmly fixed in its housing or case. Conductive support 4 may be hereinafter referred to in the specification and claims by the interchangeable terms indexing member and conductive support member." Conductive support 4 is formed of a material substantially identical with the crystal material of which crystal 3 is formed and while conductive support 4 may be a discrete'body, it is preferably integrally connected to and formed with crystal 3. Most preferably, the integral connection between the crystal and support occurs across a transverse, rigid channel or neck which extends into a thickened, elongated support body member. Integrally connected conductive support 4 is provided with discrete electrode tracks which are set off by a continuous runner and, preferably, the discrete electrode tracks and runner are continuous extensions of respective electrode tracks 5 and 6 and runner 8 provided on crystal body 3.

The crystal vibrator may be provided with its own housing which is thereafter firmly fixed in the timepiece ca se or it may be immediately fixedly mounted within the timepiece case. Once mounted within the timepiece case, the crystal vibrator may be coupled to oscillator and divider circuits by connecting coupling leads 7 and 7' thereto. For instance, the crystal vibrator may be coupled with other circuitry of the timepiece in the manner shown and described in copending application Ser. No. 212,248, filed Dec. 27, 1971, entitled "Quartz-Oscillator Controlled Timepiece Using Liquid Crystal Display Device," however, other means for interconnecting crystal vibrators in timepiece circuits are also well-known.

The crystal vibrator of this invention may be mounted within its own housing or the timepiece case by any number of well known mounting methods, provided the mounting procedure does not cause a fracture in crystal 3. For instance, the crystal vibrator housing or timepiece casing may be provided with a mounting clip for removably 'mounting conductive support member 4 of the crystal vibrator therein, alternatively, the housing or casing may be provided with a female receiving clip for removably engaging conductive support member 4 therein.

A particularly preferred mounting is shown in FIG 3, wherein a crystal vibrator 27, constructed in accordance with this invention, is provided with a discrete electrode track 28 extending downwardly along the conductive support whereat it is conductively connected to contact 30. To the other discrete electrode track 31 provided on crystal 27 and along the conductive support, a contact 32 is conductively connected. A solder is employed to make the conductive connection and the solder firmly secures the conductive support to respective contacts 30 and 32. As shown, contacts 30 and 32 rigidly secure crystal 27 to the 33 and a high Q value, as well as a shock-resistant character are obtained.

While any crystal with torsional vibrational characteristics may be employed in connection with the instant invention, provided it is of the type that may be utilized in a timepiece, it is preferable that the crystal used be of the quartz variety. The crystal itself including integrally formed conductive support member 4, may be formed by any one of a number of well known forming methods, for instance, by cutting or stamping.

Accordingly, the shock-resistance of the crystal vibrator of the instant invention is significantly higher than the concomitant shock-resistance of heretofore used conventional crystal vibrators of the type shown in FIG. 1 because the improved crystal vibrator includes a substantially rigid conductive support on which it may be mounted. Therefore, the displacement of the improved crystal vibrator in its housing or case upon impact is substantially de minimus relative to the displacement that may occur in the conventional crystal vibrator of the type shown in FIG. 1. Additionally, since conductive support 4 is itself a crystal of the same material as crystal 3, the improved crystal vibrator exhibits a high Q value and significantly contributes to the effectiveness of a quartz crystal wrist-watch.

It will thus be seen that the advantages set forth above, among those made apparent from the preceding in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

it is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and, all statements of the scope of the invention, which as a matter of language, might be said to fall therebetween.

What is claimed is:

1. A mounted vibrator for use in a timepiece comprising a crystal having a torsional vibrational mode, a pair of discrete electrode tracks deposited thereon, a continuous runner defining said discrete electrode tracks, a sole conductive support member for supporting said crystal and for conductively mounting said crystal, said conductive support being connected to said crystal and said crystal and-said conductive support being of substantially identical material, a terminal tag, said conductive support being mounted thereon, and a pair of contact pins mounted in said terminal tag; said conductive support being mounted on said'terminal tag between said contact pins, said contact pins being fixedly connected to said conductive support.

2. The mounted vibrator as claimed in claim 1 wherein said mounted crystal is substantially parallel to said terminal tag.

3. The mounted vibrator as claimed in claim 1 wherein said conductive support is substantially perpendicular to said terminal tag. 

1. A mounted vibrator for use in a timepiece comprising a crystal having a torsional vibrational mode, a pair of discrete electrode tracks deposited thereon, a continuous runner defining said discrete electrode tracks, a sole conductive support member for supporting said crystal and for conductively mounting said crystal, said conductive support being connected to said crystal and said crystal and said conductive support being of substantially identical material, a terminal tag, said conductive support being mounted thereon, and a pair of contact pins mounted in said terminal tag, said conductive support being mounted on said terminal tag between said contact pins, said contact pins being fixedly connected to said conductive support.
 2. The mounted vibrator as claimed in claim 1 wherein said mounted crystal is substantially parallel to said terminal tag.
 3. The mounted vibrator as claimed in claim 1 wherein said conductive support is substantially perpendicular to said terminal tag. 